Didn't do quite as well on the not horking bit today, but still overall vastly improved. First interval (and longest) I was fine afterwards, just winded. After the second one I started to retch a little bit but refused to stop moving and managed to "walk it off". After the third interval I tried to walk it off again but it caught up to me and I had to stop for about 30 seconds (nothing in stomach = over quickly, at least).
Logically I know I'm improving. My intervals are getting faster and longer, and even getting out there and doing ANYTHING will improve my tone and endurance. My blood pressure is ideal, and I'm taking care of my Vitamin D deficiency. I just still feel like I'm failing, because I can't run. Logically I know I'm still getting exercise, but emotionally it feels like it didn't count and I'm just wasting people's time. Meh. I dunno. I'm not giving up or anything like that, just not feeling terribly happy or optimistic with myself today.